Two passengers remain missing after Louis Cruise Lines' Sea Diamond sank in the Aegean Sea last week. A remote-controlled submersible will be sent down tomorrow to search for signs of Frenchman Jean-Christophe Allain, 45, and his 16-year-old daughter Maud. They were believed to be trapped in a flooded cabin in the lower decks, according to media reports.

Meanwhile, accident investigators questioned boatsmen on Santorini today to determine whether the crew of Sea Diamond delayed evacuation, according to the Associated Press; members of Santorini's boatsmen association played a vital part in the rescue of nearly 1,600 passengers and crew. Rescuers have repeatedly cited delays in their ability to contact the crew of the ship, though Sea Diamond engineer Stelios Peroulis denied that the rescue was mishandled, the AP reports.

As we reported yesterday, it is difficult to say at this point why the ship sank -- but the captain, speaking on Greek TV, blamed sea currents for the ill-fated collision with the volcanic rocks. "Current will most probably be a main reason as the waters there are very deep," Joyce Gleeson-Adamidis, our Under the Captain's Table columnist who's been corresponding with us from Greece, says. "There is proof of this current as the ship is still moving and settling.

"Watertight doors are to be closed while entering and leaving a port," continues Gleeson-Adamidis, whose husband was a longtime captain for Celebrity Cruises. "Since they were entering, this was probably in progress when the accident happened. The investigation will show how the water entered and when the doors were closed, and what went wrong with the process. It is reported that all was going along as should be. Often this is the case -- an accident is when we least expect it.

"Once the compartments were filled with water, preventing the sinking was impossible. There are all cliffs around this volcanic mountainous area. Waters are deep and there were no real embankments to put the ship on.

"Those who know the captain have said he is good and he is careful. It will take time for the investigators to piece it all together, but for sure those involved are at their lowest point. Careers gone. The costs in every aspect will be astronomical.

"I asked a few retired captains and hotel mangers I know their thoughts about this young captain and they all said the same thing: It would not be wise to judge him on the merit he was young; this kind of thing can happen to anyone at any time. Luck surely plays a large role in this kind of situation, and you never know what is in the future. It is every captain's nightmare -- and something they do not wish for."

Sea Diamond's captain, chief mate, second mate, third mate, chief cabin steward and housekeeper were arrested after the incident and charged with causing a shipwreck through negligence, breaching international shipping safety regulations and polluting the environment. "The housekeeper was detained due to the fact that he is responsible for making sure everyone is out of their cabins," Gleeson-Adamidis explains. "The speculation is that the two missing were in their cabin when the water started pouring in."